Searchable abstracts of presentations at key conferences on calcified tissues

ba0001pp205 | Cell biology: osteoblasts and bone formation | ECTS2013

Thrombin receptor deficiency leads to osteopetrosis by decreasing the RANKL/OPG ratio

van der Eerden BCJ , Tudpor K , Jongwattapapisan P , Woudenberg-Vrenken TE , Bindels RJM , Hoenderop JGJ , van Leeuwen JPTM

Communication between osteoblasts and osteoclasts is crucial for bone remodeling. Thrombin and its thrombin receptor (TR; PAR-1) are expressed in osteoclasts and osteoblasts, respectively. To date, the physiological roles of thrombin and TR in bone metabolism have not been elucidated. Therefore, we fully characterized the bone phenotype of mice lacking the thrombin receptor.We performed bone microarchitectural analyses of the femurs of 10–12 week ol...

ba0006is11biog | (1) (1) | ICCBH2017

IS11

van Leeuwen Hans

Biographical DetailsHans van LeeuwenHans (J.P.T.M.) van Leeuwen studied biology in Amsterdam, and did his PhD study on the mechanism of action of PTH in Leiden, The Netherlands. Currently he is professor at the Erasmus University Medical Center in Rotterdam, The Netherlands, leading the research program on Calcium and Bone Metabolism. Main research ...

ba0006is11 | (1) (1) | ICCBH2017

IS11

van Leeuwen Hans

Abstract not submitted...

ba0001pp157 | Cancer and bone: basic, translational and clinical | ECTS2013

Bone metastatic prostate cancer cells regulate their growth via impairing osteoblast differentiation

van Driel Marjolein , Robbesom Iris , Koster Ruben , Boers-Sijmons Bianca , Chiba Hideki , van Leeuwen Hans

Metastases to the bone are the incurable final outcomes of cancer, reducing both length and quality of life in an aggressive way. Despite the discoveries of many factors involved, no cure has been found. Metastatic outgrow starts in interaction with the bone micro-environment. The first attachment in bone is with the osteoblasts lining the endosteal surface. Our aim is to study the role of the osteoblasts in metastatic tumor spread and growth.We used an ...

ba0003pp190 | Genetics | ECTS2014

Premature aging of bone is delayed by dietary restriction

van der Eerden Bram , Botter Sander , Reiling Erwin , Hoeijmakers Jan , Dolle Martijn , van Leeuwen Johannes

Loss of genomic maintenance contributes to aging, as exemplified by mutations in Ercc DNA repair proteins that lead to a plethora of progeroid syndromes of which some display accelerated bone loss. It is generally accepted that dietary restriction (DR) increases life span and improves organ function. We therefore assessed the impact of DR on life span and bone mass in WT and bona fide prematurely aging hypomorphic Ercc-deficient mice (Ercc1−/Δ).<...

ba0005p158 | Cell biology: osteoblasts and bone formation | ECTS2016

A single 2-day pulse of activin-A leads to a transient change in gene expression eventually followed by reduction in extracellular matrix mineralization

Baroncelli Marta , Drabek Ksenija , Eijken Marco , Peppel Jeroen van de , van Leeuwen Johannes

Activins belong to the transforming growth factor-β superfamily, and they regulate bone formation by controlling both osteoclast and osteoblast behaviour. We have previously shown that activin-A strongly inhibited matrix mineralization in osteoblast cultures, and that activin A-signalling was most effective before the onset of mineralization.The aim of this study was therefore to investigate how an early activin-A pulse affected osteoblast mineraliz...

ba0003pp96 | Cancer and bone: basic, translational and clinical | ECTS2014

Osteoblast-secreted extracellular vesicles stimulate the expansion of CD34+ human umbilical cord blood cells

Morhayim Jess , Demmers Jeroen , van Wijnen Andre , Braakman Eric , Cornelissen Jan , de Peppel Jeroen van , van Leeuwen Hans

Introduction: Umbilical cord blood (UCB) is increasingly used in hematopoietic stem cell (HSC) transplantations; however, the low cell numbers are still remaining as a limiting factor for proper engraftment. Osteoblasts are major constituents of HSC niche and play important roles in regulating HSC self-renewal and differentiation. Recently, extracellular vesicles (EVs) have been implicated in stem cell fate regulation via horizontal transfer of proteins and nucleic acids betwe...

ba0005p61 | Bone development/growth and fracture repair | ECTS2016

Advanced phase gestational jet lag reduces bone mass of adult offspring

van der Eerden Bram , Chaves Ines , Azimzadeh Pedram , Schreuders-Koedam Marijke , Reiss Irwin , van Leeuwen Johannes , van der Horst Gijsbertus

The mammalian circadian clock is tightly controlled by clock genes, which have been shown to regulate up to 20% of the transcriptome in any given tissue. Evidence is accumulating that light-modulation perpetually affects circadian clock performance. In accordance, shift work or chronic jet lag is associated with higher risk of disease later in life, including osteoporosis. In this study, we assessed whether gestational jet lag in mice reduces bone mass postnatally.<p class...

ba0002p120 | (1) | ICCBH2013

Osteoblasts communicate with their neighbouring cells via extracellular vesicles

Morhayim Jess , Demmers Jeroen , de Jong Ton , Braakman Eric , de Peppel Jeroen van , Cornelissen Jan , van Leeuwen Hans

Objectives: Strong coordination between osteoblasts and bone marrow cells is fundamental for the regulation of healthy bone turnover and other (patho)physiological processes. Extracellular vesicles (EVs) mediate communication between cells via horizontal transfer of proteins and nucleic acids. Osteoblasts secrete EVs in the form of matrix vesicles involved in bone mineralization, however, information about a role in intercellular communication is still lacking. In this study, ...